Terrestrial carbon storage and sequestration potential of institutionally managed estates

Abstract

Many institutions have declared a climate emergency and are committed to ambitious net-zero carbon aims. However, few institutional carbon management plans consider the terrestrial carbon store of the estate in a quantitative or qualitative way. Using Newcastle University as a case study, this research demonstrated ways to quantify and potentially augment the soil and tree carbon stocks of institutional estates by changes in land management. The terrestrial carbon store of Newcastle University’s estate was quantified with field work, and scenarios of the off-setting of institutional carbon emissions were derived by considering alternative land management. Additionally, the application of wheat straw biomass and its biochar to urban soil was investigated for carbon sequestration. To quantify the current carbon storage baseline of the institutional estate, soil and tree carbon was surveyed for two research farms, campus green spaces, and a sports field. The total terrestrial carbon stock of Newcastle University’s estate was found to be 17 times greater than the annual institutional CO2 equivalents-C emissions in 2019-20. Newcastle University could off-set half of its institutional CO2 equivalents-C emissions over a period of 40 years by converting its farms into woodland. Reverting farm management to practices shown on old maps from 1900 with more permanent grasslands could off-set 64 percent of institutional CO2 equivalents-C emissions over a period of 5 years. Other measure such as doubling the number of free-standing trees on the farms, converting all lawns on the central campus into urban woodland, or amending the Newcastle Helix brownfield reclamation site soil with 2% biochar would off-set less than 3 percent of institutional emissions over 40 years. Interviews with estate, farm and carbon managers revealed reluctance to accept the dramatic land management changes which would be needed for tangible off-setting of institutional emissions, but it will be difficult to achieve net-zero carbon emission aims without serious consideration of off-setting opportunities in Newcastle University’s estate.